It is known to produce muconic acid from benzoic acid using mutant strains belonging to genus corynebacterium (Hakko Kogaku, Vol. 55, p. 95-97, 1977). Also a process using Arthrobacter sp. (DSM 20427) is known (Arch. Microboil. Vol. 110, p. 253-256).
We have extensively investigated processes for preparing muconic acid with improved productivity using benzoic acid as the carbon source, and we found microorganisms which are capable of converting benzoic acid to muconic acid at high yield. On the basis of this discovery, we completed this invention.